In the circuit of Figure P4 with indicated voltage polaritie

In the circuit of Figure P4 with indicated voltage polarities and currents directions: From KVL equation determine the voltage v_R; From the i-v characteristic of resistors determine the current i_R; Determine the power consumed or generated by the resistor. Is it consumed or generated? Base your answer according to the obtained result.

Solution

A) APPLY KVL TO LOOP CURRENT iR.

-10+12-8-VR=0

VR=-6 VOLTS.

iR=-6/3=-2 AMPS.

POWER=(-6)^2/336/3=12 WATTS.

BY OBSERVING THE VOLTAGE AND CURRENT SIGNS IT IS CONSUMING THE POWER.